Friday, December 23, 2016

Our automated jobless future.

Elizabeth Kolbert offers an interesting review of ideas in several recent books dealing with our automated future. How long will it be before you lose your job to a robot? Here are a few clips:
Imagine a matrix with two axes, manual versus cognitive and routine versus nonroutine. Jobs can then be arranged into four boxes: manual routine, manual nonroutine, and so on…Jobs on an assembly line fall into the manual-routine box, jobs in home health care into the manual-nonroutine box. Keeping track of inventory is in the cognitive-routine box; dreaming up an ad campaign is cognitive nonroutine.
The highest-paid jobs are clustered in the last box; managing a hedge fund, litigating a bankruptcy, and producing a TV show are all cognitive and nonroutine. Manual, nonroutine jobs, meanwhile, tend to be among the lowest paid—emptying bedpans, bussing tables, cleaning hotel rooms (and folding towels). Routine jobs on the factory floor or in payroll or accounting departments tend to fall in between. And it’s these middle-class jobs that robots have the easiest time laying their grippers on.
How much technology has contributed to the widening income gap in the U.S. is a matter of debate; some economists treat it as just one factor, others treat it as the determining factor. In either case, the trend line is ominous. Facebook is worth two hundred and seventy billion dollars and employs just thirteen thousand people. In 2014, Facebook acquired Whatsapp for twenty-two billion dollars. At that point, the messaging firm had a grand total of fifty-five employees. When a twenty-two-billion-dollar company can fit its entire workforce into a Greyhound bus, the concept of surplus labor would seem to have run its course.
Martin Ford (author of “Rise of the Robots: Technology and the Threat of a Jobless Future”) worries that we are headed toward an era of “techno-feudalism,” He imagines a plutocracy shut away “in gated communities or in elite cities, perhaps guarded by autonomous military robots and drones.” Under the old feudalism, the peasants were exploited; under the new arrangement, they’ll merely be superfluous. The best we can hope for, he suggests, is a collective form of semi-retirement. He recommends a guaranteed basic income for all, to be paid for with new taxes, levelled, at least in part, on the new gazillionaires.
To one degree or another, just about everyone writing on the topic shares this view. Jerry Kaplan proposes that the federal government create a 401(k)-like account for every ten-year-old in the U.S. Those who ultimately do find jobs could contribute some of their earnings to the accounts; those who don’t could perform volunteer work in return for government contributions.
...if it’s unrealistic to suppose that smart machines can be stopped, it’s probably just as unrealistic to imagine that smart policies will follow. Which brings us ... to Trump. The other day, during his “victory lap” through the Midwest, the President-elect vowed to “usher in a new Industrial Revolution,” apparently unaware that such a revolution is already under way, and that this is precisely the problem. The pain of dislocation he spoke to during the campaign is genuine; the solutions he offers are not.

Thursday, December 22, 2016

A stark graphic - the income gap continues to widen.

The NYTimes piece by Patricia Cohen and graphic summaries by Ashkenas are worth reading. The top 1% and the bottom 50% have swapped their relative shares of the national income. Forty years ago, the top 1 percent of earners took home 10.5 percent of the total national income, and the bottom half earned 20 percent of it. By 2014, those percentages effectively flipped, with the top 1 percent earning a 20 percent share and the bottom half dropping to 12.5 percent.


Wednesday, December 21, 2016

Our Arthropod housemates.

Now I know more about what is in the haze of particles I see illuminated by the horizontal rays of the rising sun flowing through my Fort Lauderdale condo in early morning.  I pass on, under the "random curious stuff" MindBlog category,  an accounting by Madden et al. that shows the ubiquity of insects detected in settled dust samples collected from inside homes. They used a DNA-based method for investigating the arthropod diversity in homes via high-throughput marker gene sequencing of home dust. Settled dust samples were collected by citizen scientists from both inside and outside more than 700 homes across the United States, yielding the first continental-scale estimates of arthropod diversity associated with our residences. Here is a graphic (click to enlarge), in which (A) shows the Genera detected, (B) shows orders detected in at least 5% of homes. The Y-axes indicate the percentage of homes (of 651 homes with arthropods detected) where those arthropods were detected.



Tuesday, December 20, 2016

Reducing future fears by suppressing episodic simulation in the brain.

Benoit et al. offer some findings relevant to understanding the heightened anxiety many are feeling in the Age of Trump.

An edited summary that starts the discussion section of their paper:
Recurrently imagining dreaded future situations potentiates fears and can even support the development and maintenance of anxiety disorders. We tested the hypothesis that such simulations can be suppressed with the opposite effect of down-regulating apprehensiveness. Our data indicate that future suppression is based on a brain mechanism that is remarkably similar to a system implicated in the voluntary suppression of past experiences. This mechanism recruits right dorsolateral prefrontal cortex, which originates an inhibitory signal that down-regulates activation in brain regions supporting both retrieval and episode-construction processes. Paralleling the suppression of recently acquired memories, the regions targeted by future suppression included the hippocampus, a structure that is fundamental for the retrieval of past episodes and the construction of coherent future and fictitious events. Critically, the suppression of recurring fears of the future differs from suppressing past events in that it also involved modulating the vmPFC (ventromedial prefrontal cortex). The mPFC fosters the integration of overlapping memories into a common representation.
A clip describing their procedure:
To examine future suppression, we adapted the “Think/No-Think” procedure, used to study the suppression of past events, to create the new “Imagine/No-Imagine” paradigm. The procedure first asked participants to describe their fears. Importantly, they only provided recurrent future fears—that is, those that they had already worried might happen before entering the experiment. Participants then gave one key detail for each fear that was typical to their recurring imaginings of it. (These typical event details served as a dependent measure; see below.) Afterward, they entered the critical Imagine/No-Imagine phase, which was composed of trials that presented reminders to these fears. For some trials, participants were asked to imagine the feared event as vividly as possible in response to the reminder (Imagine condition); for others, participants were asked to suppress their imagining of the event, upon seeing the reminder (Suppress condition). (A third of the originally provided episodes, the Baseline items, were set aside and were not cued during this phase.) Over the course of the Imagine/No-Imagine phase, participants either imagined or suppressed a feared event 12 times. Following this phase, we gave participants each reminder again and asked them to recall the typical feature of its corresponding fear. Once all typical details were tested, participants were then asked to freely imagine each episode aloud in detail for 2 min. Finally, we assessed the impact of suppression on participants’ apprehensiveness toward these future events.
Here are the significance and abstract section of their paper:
Significance 
Humans possess the remarkable ability to recombine details of divergent memories into imaginings of future events. Such imaginings are useful, for example, because they foster planning and motivate farsighted decisions. Importantly, recurrently imagining feared situations can also undermine our well-being and may even contribute to the development of anxiety. Here, we demonstrate that fearful imaginings about the future can be inhibited by neural mechanisms that help to suppress the past. Importantly, suppression reduces later apprehensiveness about the feared events, a benefit that was diminished in individuals with greater trait anxiety. This pattern suggests that the observed inhibition mechanism serves to control people’s future fears and its disruption may foster psychological disorders characterized by intrusive prospective thoughts. 
Abstract 
Imagining future events conveys adaptive benefits, yet recurrent simulations of feared situations may help to maintain anxiety. In two studies, we tested the hypothesis that people can attenuate future fears by suppressing anticipatory simulations of dreaded events. Participants repeatedly imagined upsetting episodes that they feared might happen to them and suppressed imaginings of other such events. Suppressing imagination engaged the right dorsolateral prefrontal cortex, which modulated activation in the hippocampus and in the ventromedial prefrontal cortex (vmPFC). Consistent with the role of the vmPFC in providing access to details that are typical for an event, stronger inhibition of this region was associated with greater forgetting of such details. Suppression further hindered participants’ ability to later freely envision suppressed episodes. Critically, it also reduced feelings of apprehensiveness about the feared scenario, and individuals who were particularly successful at down-regulating fears were also less trait-anxious. Attenuating apprehensiveness by suppressing simulations of feared events may thus be an effective coping strategy, suggesting that a deficiency in this mechanism could contribute to the development of anxiety.

Monday, December 19, 2016

Can evolution have a 'higher purpose'?

I want to point to this essay by Robert Wright, author of "The Moral Animal," who makes the point that arguments that life on earth may have some larger purpose do not necessarily have to depart from a scientific worldview, invoke supernatural beings, or depart from the model of evolution by natural selection. Among these arguments are:
... “simulation” scenarios, which hold that our seemingly tangible world is actually a kind of projection emanating from some sort of mind-blowingly powerful computer; and the history of our universe, including evolution on this planet, is the unfolding of a computer algorithm...When an argument for higher purpose is put this way — that is, when it doesn’t involve the phrase “higher purpose” and, further, is cast more as a technological scenario than a metaphysical one — it is considered intellectually respectable. I don’t mean there aren’t plenty of people who dismiss it. I’m talking about how people dismiss it. [Neil deGrasse Tyson and Elon Musk find this view plausible.]
Wright quotes from a conversation with William Hamilton, who says:
There’s one theory of the universe that I rather like — I accept it in an almost joking spirit — and that is that Planet Earth in our solar system is a kind of zoo for extraterrestrial beings who dwell out there somewhere. And this is the best, the most interesting experiment they could set up: to set up the evolution on Planet Earth going in such a way that it would produce these really interesting characters — humans who go around doing things — and they watch their experiment, interfering hardly at all so that almost everything we do comes out according to the laws of nature. But every now and then they see something which doesn’t look quite right — this zoo is going to kill itself off if they let you do this or that.” So, he continued, these extraterrestrials “insert a finger and just change some little thing. And maybe those are the miracles which the religious people like to so emphasize.” He reiterated: “I put it forward in an almost joking spirit. But I think it
Another scenario:
...emerges from one version of physicist Lee Smolin’s theory of “cosmological natural selection.” Smolin thinks our universe may itself be a product of a kind of evolution: maybe universes can replicate themselves via black holes, so over time — over a lot of time — you get universes whose physical laws are more and more conducive to replication. (So that’s why our universe is so good at black-hole making!) In some variants of Smolin’s theory — such as those developed by the late cosmologist Edward Harrison and the mathematician Louis Crane — intelligent beings can play a role in this replication once their technology reaches a point where they can produce black holes. So through cosmological natural selection you’d get universes whose physical properties were more and more conducive to the evolution of intelligent life. This might explain the much-discussed observation that the physical constants of this universe seem “fine-tuned” to permit the emergence of life.
Wilson's ending points:
I think discussion of higher purpose should be respectable even in a scientific age. I don’t mean I buy the simulation scenario in particular, or the space alien scenario, or the cosmological natural selection scenario. But I do think there’s reason to suspect that there’s some point to this exercise we Earthlings are engaged in, some purpose imbued by something — and that, even if identifying that something is for now hopeless, there are grounds for speculating about what the point of the exercise is.
I won’t elaborate much on this, since I’ve done that elsewhere, arguing that higher purpose can be framed as a hypothesis, and that evidence for or against the hypothesis can be marshaled. But I will say that the evidence I see for purpose includes not just the direction of biological evolution, but the direction of technological evolution and of the broader social and cultural evolution it drives — the evolution that has carried us from hunter-gatherer bands to the brink of a cohesive global community. And if the purpose involves sustaining this direction — becoming a true global community — then it would seem to include moral progress. In particular, our purpose would involve transcending the psychology of tribalism that can otherwise divide people along ethnic, national, religious and ideological lines. Which would mean — in light of recent political and social developments in the United States and abroad — that our work is cut out for us.

Friday, December 16, 2016

Political tribes, and the psychology of liberals and conservatives.

I am using this post to pass on to MindBlog readers some background material I just sent out to members of a senior current topics discussion group that we have recently formed in Fort Lauderdale, and named "The Round Table." The session on Monday Dec. 19 is on the topic indicated by the title of this post.

Where do tribes come from? Evolutionary origins   

What is essential human nature? Where do religion and morality come from?  How do  religious and non-religious people differ?  


What dynamics regulate in-group and out-group interactions and conflicts?
http://mindblog.dericbownds.net/2012/05/blog-post.html  brain correlates of whether we help someone suffering

What kinds of political tribes do people belong to today?

What distinguishes liberals and conservatives?

How do people sustain their tribal identities, what psychological shortcuts or errors help?


How can tribal animosities and conflicts be ameliorated?



Thursday, December 15, 2016

Bad things that happen to annoyingly happy people...

There is abundant evidence that being or appearing to be happy confers lots of advantages in life, both in personal health, relationships and in the workplace. On the down side, however, Ana Swanson points to work by Barasch et al. showing that very happy people are more likely to get ripped off:

Highlights
• We examine how the magnitude of expressed happiness influences social perception. 
• Very happy people are perceived as more naïve than moderately happy individuals. 
• Very happy people are believed to shelter themselves from negative information. 
• Very happy people are exploited in conflicts of interest and distributive negotiations. 
• We challenge prior work by identifying a disadvantage of expressing happiness.
Abstract
Across six studies, we examine how the magnitude of expressed happiness influences social perception and interpersonal behavior. We find that happiness evokes different judgments when expressed at high levels than when expressed at moderate levels, and that these judgments influence opportunistic behavior. Specifically, people perceive very happy individuals to be more naïve than moderately happy individuals. These perceptions reflect the belief that very happy individuals shelter themselves from negative information about the world. As a result of these inferences, very happy people, relative to moderately happy people, are more likely to receive biased advice from advisors with a conflict of interest and are more likely to be chosen as negotiation partners when the opportunity for exploitation is salient. Our findings challenge existing assumptions in organizational behavior and psychology by identifying a significant disadvantage of expressing happiness, and underscore the importance of examining emotional expressions at different magnitudes. We call for future work to explore how the same emotion, experienced or expressed at different levels, influences judgment and behavior.

Wednesday, December 14, 2016

Why does time fly when you’re having fun? Dopamine neurons…

Soares et al. find by observing timing behavior in mice that dopaminergic neurons control temporal judgments on a time scale of seconds.
Our sense of time is far from constant. For instance, time flies when we are having fun, and it slows to a trickle when we are bored. Midbrain dopamine neurons have been implicated in variable time estimation. However, a direct link between signals carried by dopamine neurons and temporal judgments is lacking. We measured and manipulated the activity of dopamine neurons as mice judged the duration of time intervals. We found that pharmacogenetic suppression of dopamine neurons decreased behavioral sensitivity to time and that dopamine neurons encoded information about trial-to-trial variability in time estimates. Last, we found that transient activation or inhibition of dopamine neurons was sufficient to slow down or speed up time estimation, respectively. Dopamine neuron activity thus reflects and can directly control the judgment of time.

Tuesday, December 13, 2016

Feeling confident that you know? fMRI correlates of metacognitive accuracy.

The more confident you are, the less likely you are to be correct! From Molenberghs et al:
One important aspect of metacognition is the ability to accurately evaluate one’s performance. People vary widely in their metacognitive ability and in general are too confident when evaluating their performance. This often leads to poor decision making with potentially disastrous consequences. To further our understanding of the neural underpinnings of these processes, this fMRI study investigated inter-individual differences in metacognitive ability and effects of trial-by-trial variation in subjective feelings of confidence when making metacognitive assessments. Participants (N = 308) evaluated their performance in a high-level social and cognitive reasoning task. The results showed that higher metacognitive accuracy was associated with a decrease in activation in the anterior medial prefrontal cortex, an area previously linked to metacognition on perception and memory. Moreover, the feeling of confidence about one’s choices was associated with an increase of activation in reward, memory and motor related areas including bilateral striatum and hippocampus, while less confidence was associated with activation in areas linked with negative affect and uncertainty, including dorsomedial prefrontal and bilateral orbitofrontal cortex. This might indicate that positive affect is related to higher confidence thereby biasing metacognitive decisions towards overconfidence. In support, behavioural analyses revealed that increased confidence was associated with lower metacognitive accuracy.

Monday, December 12, 2016

Oxytocin, moral judgement, and male social synchony

I pass on two interesting pieces of work. First, Bernhard et al. show a correlation between different forms of the oxytocin receptor gene (which would influence neurotransmitters in multiple neural systems) and the kind of judgements made in complex moral situations. The technical abstract:
Moral judgments are produced through the coordinated interaction of multiple neural systems, each of which relies on a characteristic set of neurotransmitters. Genes that produce or regulate these neurotransmitters may have distinctive influences on moral judgment. Two studies examined potential genetic influences on moral judgment using dilemmas that reliably elicit competing automatic and controlled responses, generated by dissociable neural systems. Study 1 (N = 228) examined 49 common variants (SNPs) within 10 candidate genes and identified a nominal association between a polymorphism (rs237889) of the oxytocin receptor gene (OXTR) and variation in deontological vs utilitarian moral judgment (that is, judgments favoring individual rights vs the greater good). An association was likewise observed for rs1042615 of the arginine vasopressin receptor gene (AVPR1A). Study 2 (N = 322) aimed to replicate these findings using the aforementioned dilemmas as well as a new set of structurally similar medical dilemmas. Study 2 failed to replicate the association with AVPR1A, but replicated the OXTR finding using both the original and new dilemmas. Together, these findings suggest that moral judgment is influenced by variation in the oxytocin receptor gene and, more generally, that single genetic polymorphisms can have a detectable effect on complex decision processes.
Second, Mu et al. find that oxytocin enhances inter-brain synchrony during social coordination among adult men.
Recent brain imaging research has revealed oxytocin (OT) effects on an individual's brain activity during social interaction but tells little about whether and how OT modulates the coherence of inter-brain activity related to two individuals' coordination behavior. We developed a new real-time coordination game that required two individuals of a dyad to synchronize with a partner (coordination task) or with a computer (control task) by counting in mind rhythmically. Electroencephalography (EEG) was recorded simultaneously from a dyad to examine OT effects on inter-brain synchrony of neural activity during interpersonal coordination. Experiment 1 found that dyads showed smaller interpersonal time lags of counting and greater inter-brain synchrony of alpha-band neural oscillations during the coordination (vs control) task and these effects were reliably observed in female but not male dyads. Moreover, the increased alpha-band inter-brain synchrony predicted better interpersonal behavioral synchrony across all participants. Experiment 2, using a double blind, placebo-controlled between-subjects design, revealed that intranasal OT vs placebo administration in male dyads improved interpersonal behavioral synchrony in both the coordination and control tasks but specifically enhanced alpha-band inter-brain neural oscillations during the coordination task. Our findings provide first evidence that OT enhances inter-brain synchrony in male adults to facilitate social coordination.

Friday, December 09, 2016

Exhaustion is not unique to our overstimulated age.

Anna Katharina Schaffner, author of the book "Exhaustion: A History (2016), does a precis of its arguments,
Is ours the most exhausting age ever?..The argument goes that human energy levels have basically remained static throughout history, while the cognitive, emotional and temporal demands on the modern subject have increased so sharply that a chronic deficit of inner resources ensues...
..anxieties about exhaustion are not peculiar to our age. Those who imagine that life in the past was simpler, slower and better are wrong...exhaustion and its effects have preoccupied thinkers since classical antiquity...Over the centuries, medical, cultural, literary and biographical sources have cast exhaustion as a biochemical imbalance, a somatic ailment, a viral disease and a spiritual failing. It has been linked to loss, the alignment of the planets, a perverse desire for death, and social and economic disruption.
Exhaustion theories often address questions of responsibility, agency and willpower. In some accounts, exhaustion is represented as a form of weakness and lack of willpower, or even as a grave spiritual failing manifest in a bad mental attitude. For instance, medieval theories centred around the notion of acedia and sin, while recent neoliberal theories blame individuals for the management of their physical and mental wellbeing...Acedia literally denotes a ‘state of non-caring’, and has also been described as ‘weariness of the heart’. It primarily affected monks in late antiquity and the early medieval period, and was thought to be the result of a weak spiritual disposition and giving in to demonic temptations.
In Greek antiquity, a surplus of black bile that wreaks havoc with the bodily humoral economy was blamed. In the 19th century, it was a lack of nerve-power, and in the 20th and 21st centuries, a cognitive system chronically overstrained by external stimuli and stressors.
The 19th-century American physician George M Beard invented the neurasthenia diagnosis, a vaguely defined nervous exhaustion, and declared it to be a disease of civilisation, triggered by characteristics of the modern age, including ‘steam-power, the periodical press, the telegraph, the sciences, and the mental activity of women’...A century before Beard, the Scottish physician George Cheyne (1671-1743) already theorised the ‘English Malady’, manifest in a ‘Lowness of Spirits, lethargick Dullness, Melancholy and Moping’, and which he blamed on the fast-growing wealth of the sea-faring English nation and the adverse consequences of immoderation, laziness and luxury lifestyles. Burnout theorists of the 21st century are still making similar arguments about the damaging effects of new communication technologies and the neoliberal workplace.
...the continual production of theories about the loss of human energy is also an expression of timeless anxieties about death, ageing and the dangers of waning engagement. Theorising about exhaustion, and proposing cures and therapeutics for its effects, is a tactic to counteract the awareness of our helplessness in the face of our mortality. It is, in other words, a terror-management strategy designed to hold at bay our most existential fears – fears that are in no way peculiar to today.

Thursday, December 08, 2016

The rage against the elites...

Roger Cohen, always a perceptive commentator, really nails it in his recent Op-Ed Piece "The Rage of 2016". His closing paragraphs:
Western democracies are in the midst of an upheaval they only dimly grasp. Virtual direct democracy through social media has outflanked representative democracy. The impact of the smartphone on the human psyche is as yet scarcely understood; its addictiveness is treacherous and can be the enemy of thought. Mr. Trump hijacked the Republican Party like a man borrowing a dinner jacket for an evening. His campaign moved through Twitter to the aroused masses; it had no use or need for conventional channels. The major political parties in Britain and the United States will have to prove their relevance again.
Democracies, it is clear, have not been delivering to the less privileged, who were disenfranchised or discarded in the swirl of technology’s advance. A lot of thought is now needed to find ways to restore faith in liberal, free-market societies; to show that they can be fairer and more equitable and offer more opportunities across the social spectrum. Germany, with its successful balance of capitalism and solidarity, its respect for the labor force and its commitments to both higher education and technical training, offers one model. The rage of 2016 will not abate by itself.
The liberal elites’ arrogance and ignorance has been astounding. It is time to listen to the people who voted for change, be humble and think again. That, of course, does not mean succumbing to the hatemongers and racists among them: They must be fought every inch of the way. Nor does it mean succumbing to a post-truth society: Facts are the linchpins of progress. But so brutal a comeuppance cannot be met by more of the same. I fear for my children’s world, more than I ever imagined possible.

Wednesday, December 07, 2016

We should ask our elders how best to live.

I want to point to a brief essay by Pillemer in Aeon. His interviews with several thousand people in their 80s and 90s revealed that their common response to younger people seeking a goal or purpose in life was to tell them to relax...a life can have a number of purposes, which can shift and change as life situations, interests, and priorities change.
But how should you go about finding a direction? How to settle on a purpose that fits your current life stage? One technique turns out to be immensely valuable – and yet most people ignore it. If you are searching for a direction or purpose, interview your future self...when people are made to think in detail about their future selves, they are more likely to make better financial planning decisions, show altruistic behaviour, and make more ethical choices. But it’s hard to do.
He gives advice similar to that given by Daniel Gilbert in his book "Stumbling towards happiness," a book which I abstracted in a series of MindBlog posts June 29, 2006.
..it’s astonishing how few people do the next best thing: interview an older person who embodies the ‘self’ they would like to be...In any period where you feel directionless, wavering, stuck with one foot in two different worlds, and hearing in the back of your mind the song lyrics ‘Should I stay or should I go?’ – find your future self. He or she should be old – and preferably really old. You don’t want a 40-year-old if you are 20; you want someone in his or her 80s, 90s, or a centenarian if you can find one. You need your future self to have the truly long view, as well as the detachment that comes from a very long life.
This person also needs to be as close as possible to your imagined future self. Debating a career in medicine? Find a doctor who loved what she did. Worried about whether you can balance your values with a career in the financial services industry? Find an older person who struck that balance and made it to the end of life without regrets. Planning to work an undemanding day job so you have the energy to paint/write/act in your spare time? Some very old people did just that

Tuesday, December 06, 2016

Protecting and reactivating memories

I want to point to two recent Science Magazine articles on memory. From the magazine's summaries..

Protecting memories from stress
It is widely accepted that stress has a negative impact on memory retrieval. But specific approaches to learning can counteract this effect. Smith et al. found that when memory was tested immediately after the onset of stress, stress effects were reduced. Furthermore, when subjects learned novel material by using a highly effective learning technique involving practice tests, their memory was also protected against the negative effects of stress.
Smith et al. Abstract:
More than a decade of research has supported a robust consensus: Acute stress impairs memory retrieval. We aimed to determine whether a highly effective learning technique could strengthen memory against the negative effects of stress. To bolster memory, we used retrieval practice, or the act of taking practice tests. Participants first learned stimuli by either restudying or engaging in retrieval practice. Twenty-four hours later, we induced stress in half of the participants and assessed subsequent memory performance. Participants who learned by restudying demonstrated the typical stress-related memory impairment, whereas those who learned by retrieval practice were immune to the deleterious effects of stress. These results suggest that the effects of stress on memory retrieval may be contingent on the strength of the memory representations themselves.
How to reactivate forgotten memories
Sophisticated techniques can decode stimulus representations for items held in a person's working memory. However, when subjects shift their attention toward something else, the neural representation of the now unattended item drops to baseline, as though the item has been forgotten. Rose et al. used single-pulse transcranial magnetic stimulation (TMS) to briefly reactivate the representation of an unattended item. A short pulse of TMS enhanced recognition of “forgotten” stimuli, bringing an unattended item back into focal attention.
Rose et al. Abstract:
The ability to hold information in working memory is fundamental for cognition. Contrary to the long-standing view that working memory depends on sustained, elevated activity, we present evidence suggesting that humans can hold information in working memory via “activity-silent” synaptic mechanisms. Using multivariate pattern analyses to decode brain activity patterns, we found that the active representation of an item in working memory drops to baseline when attention shifts away. A targeted pulse of transcranial magnetic stimulation produced a brief reemergence of the item in concurrently measured brain activity. This reactivation effect occurred and influenced memory performance only when the item was potentially relevant later in the trial, which suggests that the representation is dynamic and modifiable via cognitive control. The results support a synaptic theory of working memory.

Monday, December 05, 2016

Reversing the effect of booze on the brain.

Assuming that data on female rats can be extrapolated to humans, a bit of work that makes me feel better about my daily habits of aerobic swimming and a robust happy hour...Maynard and Leasure show that loss of nerve cells caused by binge drinking can be reversed by exercise, which acts to promote natural self-repair processes.:
Binge drinking damages the brain, and although a significant amount of recovery occurs with abstinence, there is a need for effective strategies to maximize neurorestoration. In contrast to binge drinking, exercise promotes brain health, so the present study assessed whether it could counteract ethanol-induced damage by augmenting natural self-repair processes following one or more binge exposures. Adult female rats were exposed to 0 (control), 1 or 2 binges, using an established 4-day model of binge-induced neurodegeneration. Half of the animals in each group remained sedentary, or had running wheel access beginning 7 days after the final binge, and were sacrificed 28 days later. To assess binge-induced hippocampal damage and exercise restoration, we quantified volume of the dentate gyrus and number of granule neurons. We found that a single binge exposure significantly decreased the volume of the dentate gyrus and number of granule neurons. A second binge did not exacerbate the damage. Exercise completely restored baseline volume and granule neuron numbers. To investigate a potential mechanism of this restoration, we administered IdU (a thymidine analog) in order to label cells generated after the first binge. Previous studies have shown that neurogenesis in the dentate gyrus is decreased by binge alcohol exposure, and that the hippocampus responds to this insult by increasing cell genesis during abstinence. We found increased IdU labeling in binge-exposed animals, and a further increase in binged animals that exercised. Our results indicate that exercise reverses long-lasting hippocampal damage by augmenting natural self-repair processes.

Friday, December 02, 2016

The brain adapts to dishonesty.

From Garrett et al., some information on neural correlates of what might be going on in Donald Trump's brain....
Dishonesty is an integral part of our social world, influencing domains ranging from finance and politics to personal relationships. Anecdotally, digressions from a moral code are often described as a series of small breaches that grow over time. Here we provide empirical evidence for a gradual escalation of self-serving dishonesty and reveal a neural mechanism supporting it. Behaviorally, we show that the extent to which participants engage in self-serving dishonesty increases with repetition. Using functional MRI, we show that signal reduction in the amygdala is sensitive to the history of dishonest behavior, consistent with adaptation. Critically, the extent of reduced amygdala sensitivity to dishonesty on a present decision relative to the previous one predicts the magnitude of escalation of self-serving dishonesty on the next decision. The findings uncover a biological mechanism that supports a 'slippery slope': what begins as small acts of dishonesty can escalate into larger transgressions.

Thursday, December 01, 2016

Genetic variants linked to education predict longevity

I'll follow yesterday's post on genetic variation and societal outcomes by passing on yet another piece, this one from Marioni et al.:

Significance
Individuals with more education tend to live longer. Genetic variants have been discovered that predict educational attainment. We tested whether a “polygenic score” based on these genetic variants could make predictions about people’s lifespan. We used data from three cohort studies (including >130,000 participants) to examine the link between offspring polygenic score for education and parental longevity. Across the studies, we found that participants with more education-linked genetic variants had longer-living parents; compared with those with the lowest genetic education scores, those with the highest scores had parents who lived on average 6 months longer. This finding suggests the hypothesis that part of the ultimate explanation for the extended longevity of better-educated people is an underlying, quantifiable, genetic propensity.
Abstract
Educational attainment is associated with many health outcomes, including longevity. It is also known to be substantially heritable. Here, we used data from three large genetic epidemiology cohort studies (Generation Scotland, n = ∼17,000; UK Biobank, n = ∼115,000; and the Estonian Biobank, n = ∼6,000) to test whether education-linked genetic variants can predict lifespan length. We did so by using cohort members’ polygenic profile score for education to predict their parents’ longevity. Across the three cohorts, meta-analysis showed that a 1 SD higher polygenic education score was associated with ∼2.7% lower mortality risk for both mothers (total ndeaths = 79,702) and ∼2.4% lower risk for fathers (total ndeaths = 97,630). On average, the parents of offspring in the upper third of the polygenic score distribution lived 0.55 y longer compared with those of offspring in the lower third. Overall, these results indicate that the genetic contributions to educational attainment are useful in the prediction of human longevity.

Wednesday, November 30, 2016

Genetic correlates of social deprivation and household income

From Hill et al.:

 Highlights
•Common SNPs (single nucleotide polymorphisms) explain 21% of social deprivation and 11% of household income 
•Two loci attained genome-wide significance for household income 
•Genes in these loci have been linked to synaptic plasticity 
•Genetic correlations were found between both measures of SES and many other traits
Summary
Individuals with lower socio-economic status (SES) are at increased risk of physical and mental illnesses and tend to die at an earlier age. Explanations for the association between SES and health typically focus on factors that are environmental in origin. However, common SNPs have been found collectively to explain around 18% of the phenotypic variance of an area-based social deprivation measure of SES. Molecular genetic studies have also shown that common physical and psychiatric diseases are partly heritable. It is possible that phenotypic associations between SES and health arise partly due to a shared genetic etiology. We conducted a genome-wide association study (GWAS) on social deprivation and on household income using 112,151 participants of UK Biobank. We find that common SNPs explain 21% of the variation in social deprivation and 11% of household income. Two independent loci attained genome-wide significance for household income, with the most significant SNP in each of these loci being rs187848990 on chromosome 2 and rs8100891 on chromosome 19. Genes in the regions of these SNPs have been associated with intellectual disabilities, schizophrenia, and synaptic plasticity. Extensive genetic correlations were found between both measures of SES and illnesses, anthropometric variables, psychiatric disorders, and cognitive ability. These findings suggest that some SNPs associated with SES are involved in the brain and central nervous system. The genetic associations with SES obviously do not reflect direct causal effects and are probably mediated via other partly heritable variables, including cognitive ability, personality, and health.

Tuesday, November 29, 2016

More exercise, less depression.

Reynolds points to a number of interesting meta-analyses that pool outcomes from past research involving more than a million men and women to show that regular exercise makes us more resistant to depression. Schuch et al. find:
...men and women with the lowest fitness were about 75 percent more likely to have been given diagnoses of depression than the people with the greatest fitness. The men and women in the middle third were almost 25 percent more likely to develop depression than those who were the most fit.
Some of the same authors pooled results from 25 studies that evaluated exercise as a treatment for depression:
...pooled results persuasively showed that exercise, especially if it is moderately strenuous, such as brisk walking or jogging, and supervised, so that people complete the entire program, has a “large and significant effect” against depression
And, on mechanisms, a clip from another Schuch et al. piece combining the results of twenty studies involving 1353 people to evaluate the neurobiological effects of exercise among people with major depressive disorder (MDD)...
The results demonstrate that a single bout of exercise increases atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), copepetin and growth hormone among people with MDD. Exercise also potentially promotes long-term adaptations of copeptin, thiobarbituric acid reactive species (TBARS) and total mean frequency (TMF). However, there is limited evidence that exercise promotes adaptations on neurogenesis, inflammation biomarkers and brain structure. Associations between depressive symptoms improvement and hippocampus volume and IL-1β were found. Nevertheless, the paucity of studies and limitations presented within, precludes a more definitive conclusion of the underlying neurobiological explanation for the antidepressant effect of exercise in people with MDD.

Monday, November 28, 2016

Networks of conforming or nonconforming individuals always reach a satisfactory state

Here is an intriguing study from Ramazi et al., who use linear-threshold-based dynamic models to show that whether individuals go with or against the crowd, a stable and satisfactory outcome results. (The model code, given in the text of the article, I don't even begin to understand...so I take their word for the results.)
Binary decisions of agents coupled in networks can often be classified into two types: “coordination,” where an agent takes an action if enough neighbors are using that action, as in the spread of social norms, innovations, and viral epidemics, and “anticoordination,” where too many neighbors taking a particular action causes an agent to take the opposite action, as in traffic congestion, crowd dispersion, and division of labor. Both of these cases can be modeled using linear-threshold–based dynamics, and a fundamental question is whether the individuals in such networks are likely to reach decisions with which they are satisfied. We show that, in the coordination case, and perhaps more surprisingly, also in the anticoordination case, the agents will indeed always tend to reach satisfactory decisions, that is, the network will almost surely reach an equilibrium state. This holds for every network topology and every distribution of thresholds, for both asynchronous and partially synchronous decision-making updates. These results reveal that irregular network topology, population heterogeneity, and partial synchrony are not sufficient to cause cycles or nonconvergence in linear-threshold dynamics; rather, other factors such as imitation or the coexistence of coordinating and anticoordinating agents must play a role.